Michigan Compiled Laws, Chapter 560. Subdivision Control Act of 1967 § 560.201a

(a) There is in effect a lease which was executed prior to January 1, 1968.

(b) The area of the land affected by the lease is smaller than the minimum lot size or configuration required by this act, or by local ordinance, as the case may be, or if the land is of proper size and configuration but at least 75% of the portion of the boundary not abutted by streets is abutted by lands of insufficient size or configuration.

(c) The leasehold premises has been improved with a permanent structure.